custom model name and id must be the same

[pkienzle]

The id for the model comes from the filename, and can be used to find and load the model on the path. The name for the model is the name displayed in the dialog box, which need not match the name of the python file.

If the name and id differs for a custom model then custom model directory processing halts with an error such as the following:

2016-09-29 07:51:39,932 ERROR Traceback (most recent call last):
  File "/Users/pkienzle/Source/sasview-new/src/sas/sasgui/perspectives/fitting/basepage.py", line 1882, in _show_combox_helper
    m_list.append(self.model_dict[str_m])
KeyError: 'myonion'

and the remaining custom models will not appear in the SasView gui.

For the file model_name.py, id is model_name and name defaults to "Model Name". We may want to change this default behaviour (defined in sasmodels/modelinfo.py:make_model_info).

[mathieu]

This has been fixed by #732